a. Solve Example 4-4 with a process simulator.

Example 4-4

A 60 mol% methanol and 40 mol% water feed is input as a two-phase mixture that flashes so that V_F/F = 0.3. Feed flow rate is 350 kmol/h. The column is well insulated and has a total condenser. The reflux is returned to the column as a saturated liquid. An external reflux ratio of L₀/D = 3.0 is used. We desire a distillate concentration of 95 mol% methanol and a bottoms concentration of 8 mol% methanol. Instead of using a reboiler, saturated steam at 1 atm is sparged directly into the bottom of the column to provide boilup (called direct or open steam). Column pressure is 1 atm. Calculate the number of equilibrium stages and the optimum feed plate location.

b. Repeat this problem but with \(\mathrm{L} / \mathrm{D}=1.5\).